std::frexp

From Cppreference

C++ Standard Library
Language Utilities library Strings library Containers library Algorithms library Iterators library Numerics library Input/output library Localizations library Regular expressions library (C++11) Atomic operations library (C++11) Thread support library (C++11)
Numerics library
Common mathematical functions
Functions Basic operations abs(int) labs llabs imaxabs (C++11) abs(float) fabs div ldiv lldiv imaxdiv (C++11) fmod remainder (C++11) remquo (C++11) fma (C++11) fmax (C++11) fmin (C++11) fdim (C++11) nan nanf nanl (C++11) (C++11) (C++11) Exponential functions exp exp2 (C++11) expm1 (C++11) log log10 log1p (C++11) log2 (C++11) Power functions sqrt cbrt (C++11) hypot (C++11) pow Trigonometric and hyperbolic functions sin cos tan asin acos atan atan2 sinh cosh tanh asinh (C++11) acosh (C++11) atanh (C++11) Error and gamma functions erf (C++11) erfc (C++11) lgamma (C++11) tgamma (C++11) Nearest integer floating point operations ceil floor round lround llround (C++11) (C++11) (C++11) trunc (C++11) nearbyint (C++11) rint lrint llrint (C++11) (C++11) (C++11) Floating point manipulation functions ldexp scalbn scalbln (C++11) (C++11) ilogb (C++11) logb (C++11) frexp modf nextafter nexttoward (C++11) (C++11) copysign (C++11) Classification fpclassify (C++11) isfinite (C++11) isinf (C++11) isnan (C++11) isnormal (C++11) signbit (C++11) Macro constants HUGE_VALF HUGE_VAL HUGE_VALL (C++11) (C++11) FP_NORMAL FP_SUBNORMAL FP_ZERO FP_INFINITE FP_NAN (C++11) (C++11) (C++11) (C++11) (C++11)

Defined in header <cmath>
float       frexp( float arg, int* exp );
double      frexp( double arg, int* exp );
long double frexp( long double arg, int* exp );
double      frexp( Integral arg, int* exp );		(since C++11)

Decomposes given floating point value to significand and exponent.

[edit] Parameters

arg	-	floating point value
exp	-	pointer to integer value to store the exponent to

[edit] Return value

significand of the given floating point number in the range of [0.5; 1). The exponent is put into integer value pointed to by exp.

[edit] See also

ldexp	multiplies a number by 2 raised to a power (function)
logb (C++11)	extracts exponent of the number (function)
ilogb (C++11)	extracts exponent of the number (function)
modf	decomposes a number into integer and fractional parts (function)